Matted fur on bunnies who shed is basically shed fur that has gotten tangled in with fur that is still attached. My two holland lops have a tendency to get mats on the sides and bottoms of their feet. The side mats got so bad at one point that they looked like fingers sticking out the sides! Our vet showed me how to deal with foot fur to deal with and prevent both side and bottom of foot shed fur……
For mats that stick out on sides of feet: *gently* pull open the tip of the mat as if you were pulling open a cottonball. Using your fingernails or tips of your fingers, pull out the shed fur from with the center of the mat. The shed fur will easily slide right out until the mat is gone and only the fluffy attached fur remains.
For mats on bottoms of feet; Using your fingernails, *gently* pull the shed fur out of the matted fur as if you were trying to remove one hair at a time. Fur on the bottoms of feet has more of a wooly texture but will easily slide out and the result will be fluffy fur left on bottoms of feet. Bunnies need plenty of soft fluffy foot fur for cushioning so never shave mats on bottoms of bunny feet.
Once feet are mat-free, inspect feet regularly. Gently pull out any loose tufts on sides of feet, and do as described above on bottoms of feet. No need to be aggressive — all you need to do is remove the shed fur! I’m always amazed at how easily the shed fur comes out!